I am having a recurrence of an issue which was initially happening in August (see this thread).
Basically YouTube videos start buffering and often play for a second or so, but then the buffer disappears and the video stops. I often get a 'An error occurred, please try again later' message after this as well. I used to be able to refresh the page a few times and it would work, but this workaround no longer functions.
Interestingly, this is less of an issue in IE, but it doesn't always work. I have the same issues on different machines at home, but not on my work machine.
Is anyone else having similar issues lately?